Steam-boiler furnace.



Patented Oct. 31, 1911.

2 SHEETSSHEET 1.

Inventor @BIWR COLUMBIA PLANOGRAPH 617., WASHINGTON, D. :1

E. E. CARR.

STEAM BOILER FURNACE.

APPLICATION FILED I'EB.13, 1911.

1,007,528, I Patented Oct. 31, 1911.

2 SHEETSSHEET 2.

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I I II I I I I I RN I H II |IIII III fil I lIIIL IIIII COLUMBIA PLANOURAPH CO.,WASH1NGTON. D. c.

ELMER E. CARE, OF CHICAGO, ILLINOIS.

STEAM-BOILER FURNACE.

Specification of Letters Patent.

Application filed February 13, 1911.

Patented Oct. 31, 1911.

Serial No. 608,429.

To all whom it may concern:

Be it known that I, ELMER E. CARR, a citizen of the United States, and resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Steam-Boiler Furnaces, of which the following is a specification, and which are illustrated in the accompanying drawings, forming a part thereof.

The invent-ion relates to steam boiler furnaces of that type in which a masonry arch is used as a cover for the fire-box of the furnace.

The principal object of the invention is to provide a masonry arch for steam boiler furnaces in which provision is made for resisting the deterioration of the arch in use by preventing the masonry materialsof the arch from attaining an excessively high temperature, and by providing for a yielding of the materials to expansion and contraction upon changes in temperature.

More specifically, the invention contemplates a furnace arch constructed from fire brick of the form commonly obtainable upon the market, such brick being so placed that spaces for the admission of air through the arch are provided, whereby an interchange of heat between the masonry materials of the arch and the air is-obtained, the air being heated to assist in the combustion of the volatile vapors distilled from the fire and the masonry materials of the arch being prevented from attaining such a high temperatlfie that deterioration would proceed rap- 1c y.

The invention therefore provides a durable construction of furnace arch, and permits of the introduction of a supplemental supply of heated air for effecting a smokeless combustion of fuel.

In the accompanying drawings, Figure 1 is a central vertical sectional view of a steam boiler furnace embodying the improvements provided by the invention; Fig. 2 is a rear end view, partly in section, of the arched roof covering the fire box of thefurnace; and Fig. 3 is a detail plan sectional view taken on the broken line 33 of Fig. 1.

.The front end wall of a steam boiler setting is shown in the drawings at 10. Details of the side walls of the setting appear at 11 and 12. The front end wall 10 has the usual fire door and ash-pit openings 13, 14. The boiler inclosed within the setting illustrated is of a form having a plurality of drums 15, 16, located in the upper part of the setting, and a drum 17 located in the lower part of the setting, the upper drums 15, 16, being connected with the drum 17 by a series of upright water tubes 18 and 19. The usual form of hand fired grate 20 is shown for simplicity of illustration. This grate extends inwardly'from the front end wall 10 to a bridge Wall. 21 located immediately in front of the lower drum 17 of the boiler. The chamber of the boiler setting is divided by baffles, as 22, 23, into a plurality o f upright combustion and flue spaces. The baffle 22 extends upwardly from the drum 17 immediately in rear of the water tubes 18, and provides a combustion and flue chamber 24 extending upwardly from the fire grate 20 to a point adjacent the top of the boiler setting. As is usual in boiler settings of this type a clean-out door opening 25 is provided in one of the side walls, as 11, of the setting.

In carrying out the invention a pair of superimposed masonry arches 26 and 27 extend over the fire grate 20 at the proper elevation to provide a fire-box of the usual depth. In the form of boiler setting shown these arches extend inwardly from the front wall 10 to a point adjacent the boiler tubes 18. The arches thus cross the front portion of the combustion and flue space 24. Communication between the chamber of the fire box below the arches and that part of the combustion and flue space 24 above the arches is provided between the inner end of the arches and the baffle 22, whereby the flames and hot gases from the fire are required to turn upwardly about the end of the arch.

It has been found that when the flames and hot gases are required to turn about the end of the arch of a steam boiler furnace in the manner just described, a triangular or pyramidal shaped portion of the arch adjacent its inner end deteriorates very rapidly, from the excessive heat and from the expansion and contraction of the masonry material from which the arch is formed, upon the changes of temperature incident to the operation of the furnace. Under these circumstances the inner or rear end portion of the arch collapses after having been used for a short period.

The invention imparts durability to the arch by allowing a yielding of the masonry materials to expansion and contraction, and

by providing for an interchange of heat bestices 29 are provided only in that part of the arch where a yielding to expansion and contraction of the materials is required, and where the materials are exposed to excessive temperature, as by the turning of the flames about the inner end of the arch.

As shown, the arch 26 is formed in two sections 30 and 31, the front section 30 being at a lower level than the rear or inner section 31. In connection with the form of boiler setting illustrated, the interstices 29 are most desirably provided between the bricks in the longitudinal rows of each of the arch sections 80 and 31, over parts of the sections of substantially triangular or pyramidal shape, the base of the pyramid in each instance being adjacent the inner or rear end of the section and the median lines of the pyramids being coincident with the longitudinal median plane of the arch. The interstices 29 provide for the passage of air from the chamber 28 downwardly through the sections of the arch into the fire-box, and for an interchange of heat between the masonry materials of the arch and the air thus introduced. In practicing the invention in connection with any form of boiler setting, the interstices 29 will be arranged in those parts of the arch which in each case are most likely to deteriorate from excessive temperature and from expansion and con traction of the masonry materials. The remainder of the arch 3a is preferably closed, as by fitting the bricks together in the usual way without interstices between them.

Provision is preferably made for the in troduction of air to the chamber 28 from outside of the boiler setting. As shown, advantage is taken of the presence of the door 25 in the side wall 11. In using the invention in connection with the boiler setting shown, this door will be left partially open for the admission of air. In this case the arch 27 is extended across the door, the open space in the wall 11 left by the presence of the door being bridged to support the arch 27 by an angle bar 32. That part of the door opening 25 above the arch 27 is then closed by brickwork 33, whereby all of the air which enters through the door opening must pass into the air chamber 28 through the space below the angle bar 32. The arch 27 is preferably also made of brick and, as shown, both of the arches 26, 27, are made from bricks of a form commonly obtainable in the market.

I claim as my invention 1.. In combination, a boiler setting having a fire grate adjacent the front wall thereof and a vertically extended combustion chamber and flue above the grate, a pair of superimposed arches extending inwardly from the said front wall of the setting over the grate and adjacent to but terminating SllOlD of the inner wall of the said combustion chamber and flue, the said arches inclosing an air chamber between them, an air duct leading to the said air chamber from without the boiler setting, the lower arch being formed of brick with interstices between the bricks extending through the said arch over only a part of the arch, the remainder of the arch being closed, the said interstices being segregated in a part of the arch of substantially pyramidal form, the axis of the pyramid being coincident with the longitudinal median line of the arch and the base of the pyramid being adjacent the inner end of the arch.

2. In combination, a steam boiler furnace having a fire grate, and an arch extending over the grate supported at its sides and at one end only and the upper side of the arch being exposed to air from without the furnace, the said arch being formed of brick arranged in longitudinal rows with interstices between adjacent bricks in the same row extending over a part of the arch only, the remainder of the arch being closed, the said interstices constituting air passages through the arch and being segregated in a part of the arch of substantially pyramidal form, the axis of the pyramid being coincident with the longitudinal median line of the arch and the base of the pyramid being adjacent the unsupported end of the arch.

ELMER E. CARR.

Witnesses:

J. IV. SMITH, L. McNnLLY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Batents, Washington, D. G. 

